25 



the atmosphere in large enough quantity to enable it under such 



conditions as obtained the past summer to retain its leaves and 



thus to prolong the period of its vegetative activity. 



Desert Botanical Laboratory, 

 Tucson, Arizona. 



SYNCARPY IN MARTYNIA LUTEA 



By J. Arthur Harris 



The fruit of Martynia is a strongly curved, beaked, loculici- 

 dally tvvo-valved capsule in which the somewhat fleshy exocarp 

 falls away in two parts and exposes the variously armed fibrous 

 woody endocarp, which dehisces from the tip of the strongly 

 curved back towards the base. On the median h'ne of the upper 

 and lower carpels or only on that of the upper carpel is produced 

 a prominent crest. In M. liitca only the upper carpel is crested.* 

 Internally the capsule is five-celled through the expansion of 

 each of the parietal placentae into two laminae which extend to 

 the wall, thus forming four lateral cells and one large central cell 

 into all of which the seeds extend from the margins of the lami- 

 nar placentae. 



In M. hitca growing on the grounds of the Missouri Botanical 

 Garden I found the two cases of syncarpy which are figured 

 here. Externally, they are identical in form while the internal 

 structure is clearly seen from the figure of the cross-section of 

 one of the fruits. The two specimens were found late in the fall 

 after the disappearance of the exocarp so that any evidence 

 offered by that part of the fruit is not available. 



The relatively greater size of the abnormal fruit is shown by 

 the cross-sections given. The relation of the elements of the 

 fruit to the peduncle is worthy of notice. In the normal fruit the 



* Here I use upper and lower in the popular instead of in the strict morphological 

 sense of dorsal and ventral. Britton and Brown in their Illustrated Flora evidently do 

 the same. They say of Mai-tymia: "the endocarp * * * crested below or also 

 above," and of Al. Louisiana Mill. [^ AI. proboscidea Glox. ) : "the endocarp 

 crested on the under side only." The figure given represents the fruit in an inverted 

 position, the horns turning downward instead of upward, so that the statement ap- 

 pears to be an oversight due to lack of familiarity with the habit of the plant. 



